Fused-Core particles have recently been introduced as an alternative to using sub-2-microm particles in chromatographic separations. Fused-Core particles are composed of a 1.7 microm solid core surrounded by a 0.5 microm porous silica layer (d(p) = 2.7 microm) to reduce mass transfer and increase peak efficiency. The performance of two commercially available Fused-Core particles (Advanced Materials Technology Halo C18 and Supelco Ascentis Express C18) was compared with sub-2-microm particles from Waters, Agilent, and Thermo Scientific. Although the peak efficiencies were only approximately 80% of those obtained by the Waters Acquity particles, the 50% lower backpressure allowed columns to be coupled in series to increase peak efficiency to 92,750 plates. The low backpressure and high efficiencies of the Fused-Core particles offer a viable alternative to using sub-2-microm particles and very-high-pressure LC instrumentation.
